Appendix E. Noise Technical Report

Transcription

1 Appendix E Noise Technical Report

2 Noise Study Report State Route 89/Fanny Bridge Community Revitalization Project Tahoe City, California District 3-Marysville-State Route 89-Bridge # California Department of Transportation, District 3 April 2014

3 For individuals with sensory disabilities, this document is available in Braille, large print, on audiocassette, or computer disk. To obtain a copy in one of these alternate formats, please call or write to Caltrans, Attn: John Holder, Caltrans Office of Specially Funded Projects, District 3, 703 B Street, Marysville, CA 95901, 530/ Voice, or use the California Relay Service TTY number,

4 Noise Study Report State Route 89/Fanny Bridge Community Revitalization Project Tahoe City, California District 3-Marysville-State Route 89-Bridge # April 2014 Prepared for: Tahoe Transportation District 128 Market Street, Suite 3F Zephyr Cove, NV (775) Contact: Alfred Knotts Transportation Project Manager Prepared by Date: Issa Mahmodi Noise Analyst/Civil Engineer AECOM 2020 L Street, Suite 400 Sacramento, CA (916) stephanie.rasmussen@aecom.com Reviewed by: Date: Jacob Nelson Environmental Protection Specialist Caltrans Office of Environmental Management District B Street Marysville, Ca (530) Jacob.nelson@dot.ca.gov Approved by: Date: John Holder Office of Specially Funded Projects District B Street Marysville, CA john_holder@dot.ca.gov

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6 Summary Summary of Findings The Tahoe Transportation District, in coordination with Placer County, U.S. Forest Service Lake Tahoe Basin Management Unit, Tahoe City Public Utility District, California Department of Transportation (Caltrans), and Federal Highway Administration is proposing improvements at and around the existing Fanny Bridge (Bridge # ) across the Truckee River as part of a community revitalization effort. The purpose of this noise study report (NSR) is to describe the existing noise environment in the project area and identify potential future traffic noise impacts associated with implementation of the State Route 89 (SR 89)/Fanny Bridge Community Revitalization Project (proposed project). The project area is located in the vicinity of Tahoe City, Placer County, California. In the Tahoe City area, SR 89 is primarily a twolane roadway built to rural design standards. At the southwest end of the Tahoe City commercial area, SR 89 intersects with SR 28 at a signalized intersection locally referred to as the North Tahoe wye. The elevation of the project area ranges from approximately 6,235 to 6,250 feet above mean sea level. In general, the topography in the project area slopes moderately downward, from 2 to 9 percent from the outer perimeter of the influence area to the shoreline of Lake Tahoe. This NSR, under the requirements of the Caltrans Traffic Noise Analysis Protocol for New Highway Construction, Reconstruction, and Retrofit Barrier Projects (Protocol), evaluates where traffic noise impacts may occur within the project area of the proposed project, potential noise abatement, and whether that abatement would be feasible. Specifically, for each receiver in the project area, this NSR describes existing and future predicted traffic noise levels for four new bridge alternatives along with two alternatives that replace and widen the existing bridge, and a no-build alternative. The four new bridge alternatives involve either reconstruction or rehabilitation of Fanny Bridge, construction of a new bridge across the Truckee River approximately 1,800 feet to the southwest, and construction on State Route (SR) 89 north of Granlibakken Road to the northwest of Fairway Drive and on SR 28 from just to the east of the SR 89 and SR 28 intersection to the SR 89 and SR 28 intersection. This NSR also addresses potential construction noise impacts associated with the proposed project. The proposed project is scheduled to start in The primary goal of the proposed project is to reduce congestion and improve the safety and operations of the SR 89/SR 28 intersection in Tahoe City, by addressing present and State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report i

7 Summary future automobile travel demand, pedestrian and bicycle mobility, public transit needs, the structural integrity of Fanny Bridge, and emergency access to West Shore communities. Alternative 1 would involve constructing a new alignment for SR 89 with a new wye at the east end of the Caltrans Maintenance Facility, and existing SR 89 would be open to local traffic only. Alternative 2 would involve constructing a new alignment for SR 89, to be located at the east end of the Caltrans Maintenance Facility, and would provide a roundabout at a new wye, closing existing SR 89 to vehicle traffic. Alternative 3 would involve constructing a new alignment for SR 89, to be located at the east end of the Caltrans Maintenance Facility, and would provide a roundabout at a new wye; existing SR 89 would be closed to vehicle traffic between the existing recreational parking access, and the Tavern Shores driveway would be turned into a cul-de-sac on the south side of the bridge. Alternative 4 is the same as Alternative 3, except that instead of a roundabout at a new wye, the intersection would be controlled with a traffic signal, and instead of a roundabout at the southern end of the 64-Acre Tract, a sweeping curve would be constructed. Alternative 6 would replace the existing Fanny Bridge with a wider structure with three northbound and two southbound travel lanes. The widened portion of the bridge would be constructed downstream of the existing structure, to comply with U.S. Bureau of Reclamation distance restrictions related to the dam. Under Alternative 6A, the existing Fanny Bridge would be replaced at its current location with a new, wider fourlane structure built to current Caltrans design and safety standards. Similar to Alternative 6, the additional 49 feet of width would be downstream of the existing structure. Under Alternative 5, the No-Build Alternative, the existing alignments would remain in place, and structural improvements would be addressed separately. Existing land uses in the project area include residential, commercial, and open space areas including single-family residences, condominiums, tennis courts, swimming pools, a golf course, hotels, motels, restaurants, and U.S. Forest Service, California Tahoe Conservancy, and State Parks lands. Potential noise impacts were assessed by investigating the existing traffic noise conditions in the project area, identifying noisesensitive locations, and predicting future traffic noise levels with and without the build alternatives. The noise receivers that were analyzed are located throughout the project area; 67 receiver points were evaluated, 30 representing hotels and motels within the project area, seven representing single-family residential units, 27 for commercial/governmental units, two for recreational areas, and one driveway. State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report ii

8 Summary Noise levels were measured at select receivers in the project area to identify existing background noise levels and validate the noise model. Loudest hour noise levels were modeled from the 67 modeled receiver locations; none of the receivers approached or exceeded the relevant equivalent continuous sound level (L eq ) of noise abatement criteria used by Caltrans and the Federal Highway Administration (FHWA). Tahoe Regional Planning Agency (TRPA) noise criteria are addressed in Appendix C. Existing noise sources in the project area include traffic on SR 89 and SR 28. In addition, commercial and recreational activities also contribute substantially to the existing noise environment. Existing peak-hour traffic noise levels at the identified receivers ranged between 38.2 dba L eq and 65.4 dba L eq. Existing peak-hour traffic noise levels at the Category B (Residential) receivers range between 39.2 dba L eq and 58.6 dba L eq. Future predicted peak-hour traffic noise levels under the No-Build Alternative (2018) at identified receivers ranged between 39.9 dba L eq and 66.9 dba L eq. The future predicted peak-hour traffic noise levels for the year 2018 ranged between 37.7 dba L eq and 64.1 dba L eq under Alternative 1, between 36.7 dba L eq and 64.1 dba L eq under Alternative 2, between 38.6 dba L eq and 64.1 dba L eq under Alternative 3, and between 36.6 dba L eq and 64.2 dba L eq under Alternative 4. The future 2018 predicted peak-hour traffic noise levels under Alternatives 6 and 6A range from 39.4 dba L eq to 64.2 dba L eq and 39.1 dba L eq to 64.2 dba L eq, respectively. Under the 2038 No-Build Alternative, future predicted peak-hour traffic noise levels at identified receivers ranged between 40.6 dba L eq and 67.2 dba L eq. The future predicted peak-hour traffic noise levels for 2038 ranged between 38.2 dba L eq and 64.4 dba L eq under Alternative 1, between 37.0 dba L eq and 64.4 dba L eq under Alternative 2, between 39.3 dba L eq and 64.1 dba L eq under Alternative 3, and between 37.1 dba L eq and 64.6 dba L eq under Alternative 4. The future 2038 predicted peak-hour traffic noise levels under Alternatives 6 and 6A range from 39.8 dba L eq to 64.6 dba L eq and 39.5 dba L eq to 64.6 dba L eq, respectively. The build alternatives would create some noise level changes over No Build Alternative. The maximum increase associated with build alternatives would be 4.2 db and 4.4 db under Alternative 4 (2018), and Alternative 4 (2038), respectively, which is below the Caltrans definition of a substantial increase (12 db). Based on the Protocol and relevant noise abatement criteria used by Caltrans and the Federal Highway Administration, no noise abatement measures were proposed at any locations in the project area. The proposed project would not expose any locations to a State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report iii

9 Summary higher noise level under any of the build alternatives in 2018 and 2038, over the existing and the No-Build Alternative conditions. No noise abatement measures are evaluated in this report; therefore, preparation of a noise abatement decision report is not required. Construction noise related to implementing the proposed project is anticipated to be typical of that for road construction. Some pavement breaking would be required; however, these activities would be temporary. Construction equipment noise may be audible at local receivers above the normal traffic noise. Night work would be required to maintain roadway operation for activities that would cross travel lanes. Nighttime construction noise would result in noise levels approximately 2 A-weighted decibels above the lowest measured ambient hourly noise level; however, these noise level increases would be temporary and would not represent a substantial increase in noise levels at local receivers. To minimize construction-related noise to the extent practical, Caltrans would implement the noise control measures described under construction noise abatement in Chapter 8, as part of standard contract requirements. TRPA has adopted standards for noise, including single-event standards for aircraft and other motorized vehicles and standards for cumulative noise events measured in terms of the 24-hour average noise metric CNEL for various land use categories and transportation corridors. The changes associated with build alternatives over the No-Build Alternative would range between and 8.5 db. As with the 2018 No-Build Alternative, the primary cause of the noise level change would be the forecasted increases in traffic volumes. However, unlike with the No-Build Alternative, some noise level changes would be a result of the proposed SR 89 alignment under each build alternative. Impacts have been identified under all 2018 build alternatives. However, all the impacted receivers would exceed the TRPA CNEL Standard of 55 dba CNEL under existing and the No-Build Alternative. Locations that would be impacted as a result of future improvements within the project area represent commercial/governmental land uses along SR 89, trails on the west side of SR 89, and an exterior hotel location on the east side of SR 89 south of the project area. Because these receivers represent commercial/governmental areas, trails, and exterior hotel locations, use of barriers for mitigation of traffic noise impacts at these locations would not be feasible or reasonable because barriers would require substantial gaps to access numerous driveways and recreation areas along SR 89. Gaps or openings in a sound wall would compromise the barrier effectiveness. In addition, there would likely be aesthetic effects of constructing barriers along the SR 89 corridor as well as further limiting access to public lands. Therefore, no noise barriers were modeled for the State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report iv

10 Summary impacted receivers and it is determined that a barrier would not be feasible or reasonable. The use of noise-reducing paving materials along the project site appears to be a feasible means of achieving a 4 to 5 db decrease in traffic noise and would reduce the potential for adverse public reaction to future traffic noise levels along the roadway. State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report v

11 Table of Contents Table of Contents Section Page Chapter 1. Introduction Purpose of the Noise Study Report Project Purpose and Need... 1 Chapter 2. Project Description Project Overview and Location Project Elements Common to Alternatives 1 through Alternatives 1-4: New Bridge Alternatives Descriptions Alternative 5: No-Build Alternative Chapter 3. Fundamentals of Traffic Noise Sound, Noise, and Acoustics Frequency Sound Pressure Levels and Decibels Addition of Decibels A-Weighted Decibels Human Response to Changes in Noise Levels Noise Descriptors Sound Propagation Geometric Spreading Ground Absorption Atmospheric Effects Shielding by Natural or Human-Made Features Chapter 4. Regulatory Setting Federal Regulations CFR State Regulations and Policies Traffic Noise Analysis Protocol for New Highway Construction and Reconstruction Projects Section 216 of the California Streets and Highways Code Local Regulations and Policies Placer County Noise Element Tahoe Regional Planning Agency Chapter 5. Study Methods and Procedures Selection of Receivers and Measurement Sites Field Measurement Procedures Long-Term (LT) Measurement Short-Term (ST) Measurements Instrumentation and Setup Meteorology Data Reduction Methods of Predicting Traffic Noise Levels Traffic Parameters Methods of Identifying Traffic Noise Impacts and Consideration of Abatement. 45 Chapter 6. Existing Noise Environment Existing Land Uses Noise Level Measurements Results State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report vi

12 Table of Contents Long-Term Monitoring Short-Term Monitoring Noise Model Calibration Estimated Noise Levels for Existing Conditions Chapter 7. Future Noise Environment, Impacts, and Considered Abatement Site Geometry and Traffic Predicted Noise Levels (2018) Traffic Noise Impacts (2018) Predicted Noise Levels (2038) Traffic Noise Impacts (2038) Noise Abatement Conclusion Feasibility of Noise Abatement Reasonable Noise Abatement Areas Where Abatement Is Not Feasible Chapter 8. Construction Noise Applicable Standards California Department of Transportation Impacts Construction Noise Abatement Chapter 9. References Chapter 10. List of Preparers Appendix A Traffic Data Appendix B TNM 2.5 Input and Output Data Appendix C TRPA - Community Noise Equivalent Level (CNEL) Analysis Appendix D Traffic Data (CNEL Calculation) Appendix E FHWA TNM 2.5 Input and Output Data (L dn or CNEL) Appendix F Supplemental Data State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report vii

13 List of Figures List of Figures Figure Page Figure 2-1: Regional Location... 2 Figure 2-2: Project Area Location... 3 Figure 2-3: Caltrans Maintenance Facility Configuration... 5 Figure 2-4: Alternative 1 New Alignment Existing SR 89 Open to Local Traffic Only... 7 Figure 2-5: Alternative 2 New Alignment Close Existing SR 89 to Vehicle Traffic... 9 Figure 2-6: Alternative 3 New Alignment Existing SR 89 Becomes a Cul-de-sac on the South Side of the Bridge Figure 2-7: Alternative 4 New Alignment, No Roundabouts Existing SR 89 Becomes a Cul-de-sac on the South Side of the Bridge Figure 2-8: Alternative 6 Replace and Widen Existing Bridge, Modify Lane Geometrics at Existing Wye Figure 2-9: Alternative 6A Replace and Widen Existing Bridge, Install Roundabout at Existing Wye Figure 5-1: Noise Measurement and Receiver Locations Figure 5-2: Long-Term Monitoring at Location LT-02, January 10 11, State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report viii

14 List of Tables List of Tables Table Page Table 3-1: Typical A-Weighted Noise Levels Table 4-1: Activity Categories and Noise Abatement Criteria Table 4-2: Placer County Maximum Allowable Noise Exposure for Transportation Noise Sources Table 4-3: TRPA Regional Plan Cumulative Noise Levels Table 5-1: Vehicle Distribution and Vehicle Speed Table 6-1: Summary of LT-01, July 5 to July 6, 2012 (Summer) Table 6-2: Summary of LT-02, January 10 to January 11, 2014 (Winter) Table 6-3: Summary of Short-Term Measurements Table 6-4: Model Calibration Table 6-5: Existing Traffic Noise Levels, dba L eq Table 7-1: Predicted Peak Noise Levels in 2018 under the No-Build and Build Alternatives Table 7-2: Maximum, Minimum, and Noise Level Changes in 2018 under the No-Build and Build Alternatives Table 7-3: Predicted Peak Noise Levels in 2038 under the No-Build and Build Alternatives Table 7-4: Future 2038 No-Build and Build Alternatives, Maximum, Minimum, and Noise Level Changes Table 8-1: Construction Equipment Noise State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report ix

15 List of Abbreviated Terms List of Abbreviated Terms ADT Average Daily Traffic AADT Annual Average Daily Traffic Caltrans California Department of Transportation CEQA California Environmental Quality Act CFR Code of Federal Regulations CNEL Community Noise Equivalent Level db Decibel(S) dba A-weighted Decibel(S) FHWA Federal Highway Administration Hz Hertz IRRS Interregional Road System Routes LD820 Larson Davis Laboratories Model 820 L dn Day-Night Level L den Day-Evening-Night Level L eq Equivalent Continuous Sound Level L eq(h) Equivalent Continuous Sound Level over 1 Hour L max Maximum Sound Level LOS Level Of Service LT Long Term L xx Percentile-Exceeded Sound Level mpa Micro-Pascal(S) mph Miles Per Hour NAC Noise Abatement Criteria NADR Noise Abatement Decision Report NEPA National Environmental Policy Act NHS National Highway System NSR Noise Study Report Protocol Caltrans s 2011 Traffic Noise Analysis Protocol for New Highway Construction, Reconstruction, and Retrofit Barrier Projects SEL Sound Exposure Level SN Serial Number SPL Sound Pressure Level SR State Route ST Short Term TCPUD Tahoe City Public Utility District TeNS Caltrans s 2009 Technical Noise Supplement State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report x

16 List of Abbreviated Terms TNM 2.5 FHWA Traffic Noise Model, version 2.5 TRPA Tahoe Regional Planning Agency USGS U.S. Geological Survey State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report xi

17 Chapter 1 Introduction Chapter 1. Introduction 1.1. Purpose of the Noise Study Report The purpose of this noise study report (NSR) is to evaluate noise impacts and abatement under the requirements of Title 23, Part 772 of the Code of Federal Regulations (23 CFR 772), Procedures for Abatement of Highway Traffic Noise. The NSR, however, also supports the noise impact analyses under CEQA, NEPA and the applicable TRPA ordinances. 23 CFR 772 provides procedures for preparing operational and construction noise studies and evaluating noise abatement considered for federal and federal-aid highway projects. According to 23 CFR 772.3, all highway projects that are developed in conformance with this regulation are deemed to be in conformance with Federal Highway Administration (FHWA) noise standards. The Caltrans Traffic Noise Analysis Protocol for New Highway Construction, Reconstruction, and Retrofit Barrier Projects (Protocol) (Caltrans 2011) provides the California Department of Transportation s (Caltrans s) policy for implementing 23 CFR 772 in California. The Protocol outlines the requirements for preparing NSRs Project Purpose and Need The purpose of the proposed project is to reduce congestion and improve the safety and operations of the SR 89/SR 28 intersection in Tahoe City, by addressing present and future automobile travel demand, pedestrian and bicycle mobility, public transit needs, the structural integrity of Fanny Bridge, and emergency access to west shore communities. Degraded traffic operations along SR 89 within the project area during summer peak periods currently create an unacceptable Level of Service (LOS) F for northbound traffic. Some or all concepts developed by the proposed project may not improve LOS to levels normally considered acceptable to one or more agencies criteria. The project innately has physical and environmental constraints that limit LOS improvement; that is, roadway lane additions on SR 28 or SR 89 would not be feasible or advisable because the existing roadways around the north and west shorelines of Lake Tahoe are predominantly two-lane highways, and Caltrans s plans do not envision adding vehicular lanes. Also, connectivity of bike/pedestrian/transit facilities is lacking in the project area and across the Truckee River. Bike/pedestrian/vehicle conflicts occur at Fanny Bridge because of the proximity of bicycles and pedestrians to traffic lanes and pedestrians State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 1

18 Chapter 1 Introduction crossing the highway. This adversely affects pedestrian and bicyclist safety, and causes vehicle operations to operate at an unacceptable LOS during peak summer hours. SR 89 bisects land managed by the U.S. Forest Service, limiting access to public land that fronts the lake adjacent to the project area. Furthermore, intermodal connectivity is lacking between vehicles, transit, bicycles, and pedestrians. Insufficient parking and access exists for recreational activities and transit. The new bus transit center is expected to accommodate existing bicycle and pedestrian paths, but those paths have limited connections east across SR 89 to access Lake Tahoe and Tahoe City. Those path connections are limited as a result of SR 89 being the primary vehicular roadway circling the west side of the lake. The seismic and structural rating of Fanny Bridge also has degraded. The structure has a bridge sufficiency rating of 52.7 and is classified as structurally deficient. Furthermore, the structure does not meet current seismic design standards and is vulnerable to failure in an earthquake. Structural improvements would be necessary even under the No-Build Alternative, as a separate project. The proposed project is needed to eliminate typical summer northbound traffic queues on SR 89, formed by volumes exceeding roadway capacity at Fanny Bridge, which have been observed to result in queues exceeding 2 miles in length and delays exceeding 1 hour, typically occurring for 4 6 hours per day. Existing capacity is reduced by the presence of pedestrians and bicyclists, both along SR 89 and crossing Fanny Bridge. Recent studies of the bridge have established that it is in need of replacement or retrofit. Opportunities to reduce dependence on automobiles, enhance the experience of pedestrians and bicyclists, improve public health and safety, achieve community plan goals, and benefit environmental conditions exists as well and could help achieve the thresholds envisioned by the TRPA. The proposed action is intended to achieve the following objectives: Relieve existing congestion on SR 89 and improve vehicle mobility for commercial needs and a better resident and visitor experience. Improve traffic safety, traffic operations, and emergency access on SR 89 and SR 28, including the river crossing (Fanny Bridge) and associated intersections. State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 2

19 Chapter 1 Introduction Improve the connectivity, reliability, travel times, and operations of public transportation modal concepts, including the mobility and safety of bicyclists and pedestrians. Improve highway freight mobility and commercial access. Improve the structural integrity of the river crossing (Fanny Bridge), and resolve safety and community concerns about the cultural values related to the historic Fanny Bridge. Make public transportation more effective with better connectivity, reliability, and travel times. Provide two viable emergency evacuation routes from the Lake Tahoe west shore communities. Reduce vehicle emissions and improve stormwater treatment. Comply with Caltrans design standards. State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 3

20 Chapter 2. Project Description Chapter 2. Project Description 2.1. Project Overview and Location The project area is located in the immediate vicinity of Truckee River Bridge # (locally known as the Fanny Bridge ) in Tahoe City, on the North Shore of Lake Tahoe in Placer County. Fanny Bridge is currently the only vehicular bridge crossing over the Truckee River that provides access to the West Shore from the north. This bridge has one 12-foot vehicular travel lane in each direction, with a 5-foot shoulder on the west side, and a 3-foot shoulder and a 5-foot sidewalk on the east side. Figures 2-1 and 2-2 show the project area boundary and regional location. Pedestrians, cyclists, and drivers are put at risk by the existing conditions of Fanny Bridge, as well as traffic congestion heading into Tahoe City along State Route (SR) 89 and at the southwest end of town. Seasonal traffic volumes cause periodic gridlock and delays in both directions, discourage transit ridership, and inconvenience residents, visitors, and businesses. The SR 89/Fanny Bridge Community Revitalization Project (proposed project) would address these deficits. There are seven project alternatives are being considered for implementation, consisting of six build and one no-build alternative (Alternative 5). Four build alternatives (Alternatives 1 through 4) would result in the construction of a new bridge over the Truckee River and realignment of SR 89. Two build alternatives (Alternatives 6 and 6A) would replace and widen the existing Fanny Bridge and would maintain the existing SR 89/ SR 28 intersection location. The build alternatives address the project needs of improving seasonal traffic congestion and air quality, providing bike/pedestrian connectivity, improving transit operations, improving bicycle and pedestrian safety, and addressing the structural integrity of Fanny Bridge. By relieving congestion on SR 89, the project would improve vehicle mobility for commerce needs and for resident and visitor experiences. Alternatives 1 through 4 would also provide a second crossing over the Truckee River that would aid emergency evacuation from the west shore of Lake Tahoe Project Elements Common to Alternatives 1 through 4 The four new bridge alternatives would include the realignment of SR 89 to a point approximately 1,800 feet southwest of the existing SR 89/SR 28 intersection (known as the wye ). SR 89 would be realigned from the Caltrans Maintenance Facility, over the State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 1

21 Chapter 2. Project Description Source: Data adapted by AECOM in 2014 Figure 2-1: Regional Location State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 2

22 Chapter 2. Project Description Source: Data adapted by AECOM in 2014 Figure 2-2: Project Area Location State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 3

23 Chapter 2. Project Description Truckee River and east through the U.S. Forest Service (USFS) 64-Acre Tract, to reconnect to existing SR 89 near the existing changeable message sign and sled hill. SR 28 would be extended from the existing wye to the new SR89/SR 28 intersection. A portion of the existing SR 89 would become a local road for approximately 2,000 feet south of SR 28, or would be re-constructed as a cul-de-sac. Alternatives 1 through 4 would include either reconstruction or rehabilitation of the existing Fanny Bridge and the potential removal of the free right-turn lanes at the existing wye. In addition to the roadway realignment, all of the new bridge alternatives would also include modification to the Caltrans Maintenance Facility; relocation of the Tahoe- Truckee Sanitation Agency (TTSA) sewer line beneath SR 89 near the Caltrans Maintenance Facility; and realignment of portions of the existing Class I bike paths on both sides of the Truckee River. The existing bike path would be rerouted over the new bridge and reconnected with existing bike paths in the 64-Acre Tract. These common elements are described in more detail below. NEW BRIDGE OVER THE TRUCKEE RIVER A new bridge over the Truckee River would be located approximately 1,800 feet southwest of the existing Fanny Bridge. The bridge would have three 12-foot throughtraffic lanes (one eastbound and two westbound) and 8-foot shoulders on each side. The bridge would include a separated Class I bike path on the west side for the Truckee River bike trail. The bike path would be separated from vehicular traffic with a concrete barrier and would be 10-feet wide with a 3-foot eastern shoulder and a 4-foot western shoulder. The width of the proposed bridge would range from 80 feet at the eastern abutment to 100 feet at the western abutment. The structure would widen on the western abutment, under Alternatives 1, 2, and 3, to accommodate the approach to the proposed western roundabout. The structure would use precast concrete girders and context sensitive railings would be constructed along each edge of the bridge. Aesthetic treatments would be included in the design and construction of the bridge to be compatible with the surrounding natural and human environments. A minimum 10 feet of clearance for nonmotorized watercraft would be below the bridge under normal water level conditions, and 10 feet of clearance over the Tahoe Rim Trail on the eastern shore of the Truckee River. Slope retaining structures with appropriate drainage would be constructed, as required, along the portions of SR 89 that would be widened. State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 4

24 Chapter 2. Project Description Source: Wood Rodgers; Adapted by AECOM in 2014 Figure 2-3: Caltrans Maintenance Facility Configuration State Route 89/Fanny Bridge Community Revitalization Project 5

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26 Chapter 2. Project Description Source: Data provided by Wood Rodgers and adapted by AECOM in 2014 Figure 2-4: Alternative 1 New Alignment Existing SR 89 Open to Local Traffic Only State Route 89/Fanny Bridge Community Revitalization Project 7

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28 Chapter 2. Project Description Source: Data provided by Wood Rodgers and adapted by AECOM in 2014 Figure 2-5: Alternative 2 New Alignment Close Existing SR 89 to Vehicle Traffic State Route 89/Fanny Bridge Community Revitalization Project 9

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30 Chapter 2. Project Description Source: Data provided by Wood Rodgers and adapted by AECOM in 2014 Figure 2-6: Alternative 3 New Alignment Existing SR 89 Becomes a Cul-de-sac on the South Side of the Bridge State Route 89/Fanny Bridge Community Revitalization Project 11

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32 Chapter 2. Project Description Source: Data provided by Wood Rodgers and adapted by AECOM in 2014 Figure 2-7: Alternative 4 New Alignment, No Roundabouts Existing SR 89 Becomes a Cul-de-sac on the South Side of the Bridge State Route 89/Fanny Bridge Community Revitalization Project 13

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34 Chapter 2 Project Description FANNY BRIDGE Following construction of the new bridge, Fanny Bridge would either be rehabilitated or replaced with a new structure to address structural and seismic deficiencies. A replaced Fanny Bridge would be the same width as the existing bridge and have similar architecture. With the bridge no longer serving as a state highway, a replaced bridge would allow for reduced 11-foot lanes, and 3-foot shoulders. This would allow for a sidewalk to be added to the west (downstream) side of the bridge. Rock slope protection may be required to provide scour protection. FREE RIGHT-TURN LANE MODIFICATIONS Alternatives 1 through 4 would include three options for the existing free right-turn lanes at the existing SR 89/SR 28 intersection. Option 1 Parking Spaces Under Option 1, the existing free right-turn lanes would be replaced with approximately 55 parking spaces. The landscaped median at the southeast corner of the intersection would be removed and replaced with a parking lot, and the existing free right-turn lanes would be restriped with parking spaces. The free right turns would be closed to through traffic, and all right turns would be directed through the signalized intersection. Option 2 Landscaping Under Option 2, the free right-turn lanes would be replaced with expanded landscaping. The landscaped medians at the southeast and southwest corners of the intersection would be expanded to include the existing free right turns. All right turns would be directed through the signalized intersection. Option 3 Minor Modifications Under Option 3, minor modifications would be made to the existing free-right-turn lanes. The lanes would be reduced to 13 feet. The existing landscaped medians would be expanded and pedestrian facilities in the area would be enhanced. MODIFICATIONS TO THE CALTRANS MAINTENANCE FACILITY Under Alternatives 1 through 4, the primary ingress and egress to the Caltrans Maintenance Facility (the Caltrans Tahoe City Maintenance Station) would be relocated from its current location at the northeastern end of the maintenance yard to a modified entrance at the western end (Figure 1-3). The profile of the new western entrance would be raised 10 feet higher than the existing conditions, and a wall would be constructed at the existing entrance to prohibit access. Fuel tanks, pumping facilities, and a pole barn would be demolished and relocated within the maintenance yard. In addition, the entire State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 15

35 Chapter 2 Project Description area between the new driveway and SR 89 would be used as storage for snow or other materials. The existing bike path would be realigned and a short tunnel would be constructed beneath the new entrance to accommodate bicycle traffic (i.e., through the embankment of the new entrance). RELOCATION OF THE TAHOE TRUCKEE SANITATION AGENCY SEWER LINE The Truckee River Interceptor (TRI) pipeline is a trunk sewer line that serves the North Tahoe Public Utility District, the Tahoe City Public Utility District (TCPUD), the Alpine Springs County Water District, the Squaw Valley Public Service District, and the Truckee Sanitary District. It is owned and operated by the TTSA. A portion of the TRI sewer line is located beneath the area of the proposed roundabout or intersection near the Caltrans Maintenance Facility and would require relocation. Alternatives 1 through 4 would include installation of new manholes and relocation of the TRI sewer line, either beneath or around the western roundabout (or signalized intersection) at the western end of the new SR 89 alignment. Flow monitoring equipment would also be relocated to one of the new manhole locations. This relocation would be completed within existing disturbed areas (e.g., within roadway) and would be sized to maintain the existing flow capacity. BIKE PATH REALIGNMENT Portions of the existing Class I bike paths in the project area would be realigned as part of implementation of any of the new bridge alternatives, as described below. SOUTH SIDE OF RIVER Beginning at the McClintock Building on SR 89, north of Granlibakken Road, the existing bike path would turn west onto a new alignment for 580 feet. It would then rejoin the existing path and would continue toward the Truckee River. At the river, the path would shift closer to the river and would go underneath the new Truckee River Bridge before rejoining the existing path, near the existing recreational parking lot. The existing bike path, which runs parallel to SR 89 between the McClintock Building and the Tahoe City Transit Center (Transit Center), would remain. The segment of bike path along SR 89, between the Transit Center and Fanny Bridge, would be converted to sidewalk. Bicycles would be directed to use a new Class II bike lane on the existing SR 89, which would be relinquished by Caltrans and would be designated as a local Placer County road with implementation of the proposed project. State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 16

36 Chapter 2 Project Description NORTH SIDE OF RIVER Beginning east of the Tahoe City Lumber/Ace Hardware entrance on SR 89, the existing Truckee River Class I bike path would be shifted south towards the Caltrans Maintenance Facility and would go underneath the new Maintenance Facility driveway in a short tunnel through the driveway embankment. At the new Truckee River Bridge, the bike path would go over the new bridge and join the trail on the south side of the Truckee River near the Tahoe Rim Trail. The bike trail would be separated from vehicle traffic over the bridge to improve safety. The existing segment of trail between the new Truckee River Bridge and the existing pedestrian bridge would be demolished. CONSTRUCTION TECHNIQUES Alternatives 1 through 4 would incorporate the following construction techniques and practices. In-Water Construction and Groundwater Construction of any new bridges across the Truckee River would require dewatering for construction activities that would encounter groundwater, including: installation of the bridge footings and utility demolition, replacement, and protection. As necessary during construction, water-tight coffer dams would be installed temporarily to prevent scour and to maintain soil- and water-free footings, to allow for pile driving. After the footings were constructed, the coffer dams would be removed and the remaining portion of the bridge would be constructed from outside the Truckee River. The river bottom would be restored to its original condition and elevation when work within the river is completed. Water pumped from excavation activities would contain suspended sediments and other solids, as measured by total dissolved solids. The suspended sediments would not be discharged directly into the Truckee River, stream environment zones (as defined by Tahoe Regional Planning Agency [TRPA]), wetlands (as defined by the U.S. Army Corps of Engineers [USACE]), or municipal storm drains. Filtration devices and systems would be provided to remove suspended sediments that were generated during dewatering activities. Pumped water would be discharged in compliance with all applicable laws and permit requirements. If any groundwater to be dewatered or any accumulated stormwater runoff contained elevated levels of regulated constituents, the contaminated water would be pumped and disposed at a permitted waste disposal facility meeting all applicable laws and regulations. Utility work is expected to take several weeks to complete. Bridge footing work within the Truckee River is anticipated to take approximately 2 to 3 months and would be completed during the summer months. State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 17

37 Chapter 2 Project Description Construction best management practices (BMPs) would be implemented, in compliance with all permits and Caltrans requirements. Traffic Control Measures Traffic control would be required during project construction, to minimize lane closure requirements, preserve access to businesses, and minimize travel delays. These strategies would be implemented in conformance with Caltrans and County standards as they would apply to each stage of construction. Rehabilitation or replacement of Fanny Bridge would require periods of reduced lane widths and lane closures on the existing bridge, and a short period of full bridge closure. Bridge closure would affect traffic and accessibility to and from the West Shore. The new Truckee River Bridge would be constructed prior to the construction on Fanny Bridge to allow for detour of traffic and to maintain a crossing over the Truckee River at all times. Closures could potentially be scheduled in late spring or early fall to reduce impacts on businesses, residents, and visitors during the summer peak season. However, this may not be feasible due to the short construction season within the Tahoe Basin (May 1 through October 15). As with Alternatives 1 4, emergency service providers would be notified about any planned lane closures and reduced lane widths, and a traffic management plan would be prepared to specify how emergency services would be provided during temporary closures. Traffic control measures would include: temporary signage, lane width reductions, reduced speeds, and detours over the new bridge Alternatives 1-4: New Bridge Alternatives Descriptions While the components described above would be the same under each new bridge alternative, the configurations of the roadways and associated features would differ as described below. ALTERNATIVE 1 NEW ALIGNMENT EXISTING SR 89 OPEN TO LOCAL TRAFFIC ONLY Under Alternative 1, SR 89 would be realigned as a new two-lane segment of roadway that would cross through USFS s 64-Acre Tract. The western end of the new segment would begin at a new single-lane roundabout, which would serve as the new SR 89/SR 28 intersection. A new bridge over the Truckee River would be constructed immediately southeast of the roundabout on the new roadway segment. The new alignment would continue east and would reconnect to existing SR 89 at a single-lane roundabout near the existing changeable message sign and sled hill (see Figure 1-4). Retaining walls, 10 to 15 feet in height, would be required around the western roundabout because the roadway would need to be raised approximately 10 feet at the roundabout to provide sufficient clearance for the new bridge over the river. To implement Alternative 1, acres State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 18

38 Chapter 2 Project Description would have to be acquired for right-of-way (ROW); however, no businesses or residences would need to be relocated as a result of these acquisitions, and access would be maintained to all parcels affected by the alternative. Fanny Bridge would be rehabilitated or replaced to address the existing structural deficiencies and resolve safety and community concerns related to the project objectives. The existing section of SR 89 between Fanny Bridge and the eastern roundabout would be relinquished to Placer County and would become a local street. Traffic calming and aesthetic features would be installed within this section of roadway (e.g., a reduced speed limit, bulb-outs, landscaped areas, raised landscaped median, on-street parking, sidewalks, street lighting, and benches). New parking or landscaping may replace the existing free right turns. Alternative 1 would include signage to indicate to drivers the direction to Truckee, Tahoe City, and South Lake Tahoe. Signs would be placed near all entry points to the roundabouts. Signs for gas, food, lodging, public transportation, hiking trails, and other tourist amenities would direct travelers toward Tahoe City attractions and businesses. In addition, the entrance into the Transit Center would be realigned to allow for bus and vehicle access approximately 240 feet north of the eastern roundabout. ALTERNATIVE 2 NEW ALIGNMENT CLOSE EXISTING SR 89 TO VEHICLE TRAFFIC Under Alternative 2, the SR 89 realignment and signage would be the same as described under Alternative 1. Fanny Bridge would be rehabilitated or replaced to address the existing structural deficiencies and resolve safety and community concerns related to the project objectives. The existing section of SR 89 between Fanny Bridge and the new eastern roundabout would be relinquished to Placer County and would become a local street (see Figure 1-5). Similar to Alternative 1, under Alternative 2, acres would have to be acquired for ROW; however, no businesses or residences would need to be relocated as a result of these acquisitions, and access would be maintained to all parcels affected by the alternative. A new bridge, which would serve as the primary river crossing, would be constructed over the Truckee River near the east end of the Caltrans Maintenance Facility. Bollards would be placed to the north and south of Fanny Bridge to prohibit vehicular traffic. Access on this portion of the former SR 89 would be provided only for pedestrians, bicyclists, and emergency vehicles. New parking or landscaping may replace the existing free-right turns. Entry into the Transit Center would be allowed from the south only, at a point access approximately 240 feet north of the single-lane roundabout. Traffic calming State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 19

39 Chapter 2 Project Description improvements similar to those described for Alternative 1 would be constructed on the street south of Fanny Bridge. ALTERNATIVE 3 NEW ALIGNMENT EXISTING SR 89 BECOMES A CUL-DE-SAC ON THE SOUTH SIDE OF THE BRIDGE Under Alternative 3, the SR 89 realignment and signage would be the same as described under Alternatives 1 and 2. Fanny Bridge would be rehabilitated or replaced to improve the existing structural integrity and resolve safety and community concerns related to the project objectives. The existing section of SR 89 between Fanny Bridge and the eastern roundabout would be relinquished to Placer County and would become a local street (see Figure 1-6). To implement Alternative 3, acres would have to be acquired for ROW; however, no businesses or residences would need to be relocated as a result of these acquisitions. Unlike Alternatives 1 and 2, Alternative 3 would affect access to several parcels, including the Tahoe Tavern Properties and the Bank of the West parcel. A new bridge, which would serve as the primary river crossing, would be constructed over the Truckee River near the east end of the Caltrans Maintenance Facility. Access to Fanny Bridge would be available only from the north, via SR 28. A cul-de-sac would be constructed on the southern side of Fanny Bridge. The existing SR 89 would no longer allow access to Fanny Bridge from the south. It would provide access only to the Transit Center and would offer a secondary Truckee River crossing for emergency vehicles, if necessary. Buses would be allowed to enter the Transit center either from the cul-de-sac or the single-lane roundabout; vehicle entry to the Transit Center would be limited to the eastern roundabout. New parking or landscaping may replace the existing free-right turns. The SR 89/28 intersection modifications and signage would be the same under Alternative 3 as described for Alternative 1 and 2. ALTERNATIVE 4 NEW ALIGNMENT, NO ROUNDABOUTS EXISTING SR 89 BECOMES A CUL- DE-SAC ON THE SOUTH SIDE OF THE BRIDGE Under Alternative 4, the SR 89 realignment would follow a similar alignment as described above under Alternative 1. However, the two-lane roundabout at the SR 89/SR 28 junction would be replaced with a traditional signalized intersection and a sweeping curve, diverting vehicles onto realigned SR 89, would replace the eastern roundabout (see Figure 1-7). To implement Alternative 4, acres would have to be acquired for ROW; however, no businesses or residences would need to be relocated as a result of these acquisitions. As under Alternative 3, access to several parcels from the south would be affected. Although State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 20

40 Chapter 2 Project Description the changes in access would reduce traffic congestion adjacent to these parcels, access to and from the south would be much longer and less direct. A new bridge, which would serve as the primary river crossing, would be constructed over the Truckee River near the east end of the Caltrans Maintenance Facility. Fanny Bridge would be rehabilitated or replaced to improve the existing structural integrity and resolve safety and community concerns related to the project objectives. Fanny Bridge and the existing section of SR 89 south of Fanny Bridge would undergo the same rehabilitation as described under Alternative 3. The SR 89/SR 28 intersection modifications and signage would be the same under Alternative 4 as described under Alternatives 1, 2, and 3. Buses would be allowed to enter the Transit Center, either from the cul-de-sac or the single-lane roundabout; car entry to the Transit Center would be limited to the new entrance off of the realigned segment Alternative 5: No-Build Alternative Alternative 5 is the No-Build Alternative. Under this alternative, no improvements would be made to SR 89, the SR 89/SR 28 intersection, or Fanny Bridge. Any actions required to address the bridge s structural deficiencies would not be completed by the Tahoe Transportation District (TTD). Another agency (such as Caltrans or Placer County) could pursue a separate bridge rehabilitation or replacement project, or gradual upgrades may be implemented through routine maintenance by Caltrans. Alternatively, Caltrans could declare a more stringent vehicle weight restriction. At this time, no specific improvements to the bridge are planned by Caltrans or another agency. Because no roadway improvements to improve traffic circulation or safety would be made under Alternative 5, no land acquisitions for ROW would occur under this alternative. ALTERNATIVE 6 AND 6A: REPLACE AND WIDEN EXISTING BRIDGE Under Alternatives 6 and 6A, the existing Fanny Bridge structure would be replaced with a wider structure and changes to the profile may be required. These alternatives would not include the project components described in Section 1.1.1, Project Elements Common to Alternatives 1 through 4. Although construction of Alternative 6 or Alternative 6A would not affect the existing bicycle paths or other facilities in the 64- Acre Tract, access to the 64-Acre Tract on either side of SR 89 could be blocked temporarily during construction. If Fanny Bridge was closed during construction, as would be likely to occur at times, access to the 64-Acre Tract by vehicle would not be possible from the north. Access to bicycle paths would still be possible by using the existing pedestrian/bicycle bridge. State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 21

41 Chapter 2 Project Description The following provides specifics related to Alternatives 6 and 6A. ALTERNATIVE 6 REPLACE AND WIDEN EXISTING BRIDGE, MODIFY LANE GEOMETRICS AT EXISTING WYE INTERSECTION Alternative 6 would replace the existing Fanny Bridge with a wider structure having three northbound and two southbound travel lanes. The widened portion of the bridge would be constructed downstream from the existing structure, to comply with U.S Bureau of Reclamation (Reclamation) distance restrictions related to the dam. Therefore, the new bridge would be 60 feet wider, and the centerline would be 28 feet downstream, as compared to the existing structure. The new Fanny Bridge would have 12-foot travel lanes, 8-foot shoulders, and 10-foot sidewalks on both sides. Under this alternative, the wye would remain in its existing location and configuration; however, the free right-turn lanes at the wye would be removed and would be replaced with right-turn lanes that would direct vehicles through the signalized intersection (Figure 2-8). To implement Alternative 6, acre of ROW would be acquired; three of these acquisitions could require full take of property. Should full take be needed for the acquisitions, the total ROW acquired would be acres. In addition, an existing structure on the Liberty Power parcel would have to be relocated within that parcel. Access would be maintained to all parcels affected by this alternative. ALTERNATIVE 6A REPLACE AND WIDEN EXISTING BRIDGE, INSTALL ROUNDABOUT AT EXISTING WYE INTERSECTION Under Alternative 6A, the existing Fanny Bridge would be replaced at its current location with a new, wider four-lane structure built to current Caltrans design and safety standards. Similar to Alternative 6, the additional 49 feet in width would be downstream from the existing structure. The centerline of the new bridge would be 22 feet downstream from the centerline of the existing bridge. The new Fanny Bridge would have 12-foot travel lanes, 8-foot shoulders, and 10-foot sidewalks on both sides. The existing signalized wye intersection would be replaced with a two-lane roundabout (Figure 1-9). To implement Alternative 6A, acre of ROW would be acquired; two of these acquisitions could require full take of the property. Should full take be needed for the acquisitions, the total ROW acquired would be acres. In addition, as under Alternative 6, an existing structure on the Liberty Power parcel would have to be relocated within that parcel. Access would be maintained to all parcels affected by this alternative. State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 22

42 Chapter 2 Project Description Source: Data provided by Wood Rodgers and adapted by AECOM in 2014 Figure 2-8: Alternative 6 Replace and Widen Existing Bridge, Modify Lane Geometrics at Existing Wye State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 23

43 Chapter 2 Project Description Source: Data provided by Wood Rodgers and adapted by AECOM in 2014 Figure 2-9: Alternative 6A Replace and Widen Existing Bridge, Install Roundabout at Existing Wye State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 24

44 Chapter 3 Fundamentals of Traffic Noise Chapter 3. Fundamentals of Traffic Noise This section discusses fundamental traffic noise concepts. For a more detailed discussion, please refer to Caltrans s Technical Noise Supplement (TeNS) (Caltrans 2009), a technical supplement to the Protocol that is available on the Caltrans Web site ( Sound, Noise, and Acoustics Sound can be described as the mechanical energy of a vibrating object transmitted by pressure waves through a liquid or gaseous medium (e.g., air) to a hearing organ, such as a human ear. Noise is defined as loud, unexpected, or annoying sound. In the science of acoustics, the fundamental model consists of a sound (or noise) source, a receiver, and the propagation path between the two. The loudness of the noise source and obstructions or atmospheric factors affecting the propagation path to the receiver determines the sound level and characteristics of the noise perceived by the receiver. The field of acoustics deals primarily with the propagation and control of sound Frequency Continuous sound can be described by frequency (pitch) and amplitude (loudness). A low-frequency sound is perceived as low in pitch. Frequency is expressed in terms of cycles per second, or Hertz (Hz) (e.g., a frequency of 250 cycles per second is referred to as 250 Hz). High frequencies are sometimes more conveniently expressed in kilohertz, or thousands of Hertz. The audible frequency range for humans is generally between 20 Hz and 20,000 Hz Sound Pressure Levels and Decibels The amplitude of pressure waves generated by a sound source determines the loudness of that source. Sound pressure amplitude is measured in micro-pascals (mpa). One mpa is approximately one hundred billionth ( ) of normal atmospheric pressure. Sound pressure amplitudes for different kinds of noise environments can range from less than 100 to 100,000,000 mpa. Because of this huge range of values, sound is rarely expressed in terms of mpa. Instead, a logarithmic scale is used to describe sound pressure level (SPL) in terms of decibels (db). The threshold of hearing for young people is about 0 db, which corresponds to 20 mpa. State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 25

45 Chapter 3 Fundamentals of Traffic Noise 3.4. Addition of Decibels Because decibels are logarithmic units, SPL cannot be added or subtracted through ordinary arithmetic. Under the decibel scale, a doubling of sound energy corresponds to a 3-dB increase. In other words, when two identical sources are each producing sound of the same loudness, the resulting sound level at a given distance would be 3 db higher than one source under the same conditions. For example, if one automobile produces an SPL of 70 db when it passes an observer, two cars passing simultaneously would not produce 140 db; rather, they would combine to produce 73 db. Under the decibel scale, three sources of equal loudness together produce a sound level 5 db louder than one source A-Weighted Decibels The decibel scale alone does not adequately characterize how humans perceive noise. The dominant frequencies of a sound have a substantial effect on the human response to that sound. Although the intensity (energy per unit area) of the sound is a purely physical quantity, the loudness or human response is determined by the characteristics of the human ear. Human hearing is limited in the range of audible frequencies as well as in the way it perceives the SPL in that range. In general, people are most sensitive to the frequency range of 1,000 8,000 Hz, and perceive sounds within that range better than sounds of the same amplitude in higher or lower frequencies. To approximate the response of the human ear, sound levels of individual frequency bands are weighted, depending on the human sensitivity to those frequencies. Then, an A-weighted sound level (expressed in units of A-weighted decibels [dba]) can be computed based on this information. The A-weighting network approximates the frequency response of the average young ear when listening to most ordinary sounds. When people make judgments of the relative loudness or annoyance of a sound, their judgment correlates well with the A-scale sound levels of those sounds. Other weighting networks have been devised to address high noise levels or other special problems (e.g., B-, C-, and D-scales), but these scales are rarely used in conjunction with highway-traffic noise. Noise levels for traffic noise reports are typically reported in terms of A-weighted decibels or dba. Table 3-1 describes typical A- weighted noise levels for various noise sources. State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 26

46 Chapter 3 Fundamentals of Traffic Noise Table 3-1: Typical A-Weighted Noise Levels Common Outdoor Activities Jet fly-over at 1,000 feet Gas lawn mower at 3 feet Diesel truck at 50 feet at 50 miles per hour Noisy urban area, daytime Noise Level (dba) Common Indoor Activities 110 Rock band Food blender at 3 feet 80 Garbage disposal at 3 feet Gas lawn mower, 100 feet 70 Vacuum cleaner at 10 feet Commercial area Heavy traffic at 300 feet 60 Normal speech at 3 feet Large business office Quiet urban daytime 50 Dishwasher next room Quiet urban nighttime 40 Quiet suburban nighttime Quiet rural nighttime Theater, large conference room (background) 30 Library Bedroom at night, concert Broadcast/recording studio Lowest threshold of human hearing 0 Lowest threshold of human hearing Source: Caltrans Human Response to Changes in Noise Levels As discussed above, the doubling of sound energy results in a 3-dB increase in sound. However, given a sound level change measured with precise instrumentation, the subjective human perception of a doubling of loudness will usually be different from what is measured. Under controlled conditions in an acoustical laboratory, the trained, healthy human ear is able to discern 1-dB changes in sound levels when exposed to steady, single-frequency State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 27

47 Chapter 3 Fundamentals of Traffic Noise ( pure-tone ) signals in the mid-frequency (1,000 8,000 Hz) range. In typical noisy environments, changes in noise of 1 2 db are generally not perceptible. However, it is widely accepted that people are able to begin to detect sound level increases of 3 db in typical noisy environments. Further, a 5-dB increase is generally perceived as a distinctly noticeable increase, and a 10-dB increase is generally perceived as a doubling of loudness. Therefore, a doubling of sound energy (e.g., doubling the volume of traffic on a highway) that would result in a 3-dB increase in sound would generally be perceived as barely detectable Noise Descriptors Noise in our daily environment fluctuates over time. Some fluctuations are minor, but some are substantial. Some noise levels occur in regular patterns, but others are random. Some noise levels fluctuate rapidly, but others fluctuate slowly. Some noise levels vary widely, but others are relatively constant. Various noise descriptors have been developed to describe time-varying noise levels. The following are the noise descriptors most commonly used in traffic noise analysis. Equivalent Continuous Sound Level (L eq ): L eq represents an average of the sound energy occurring over a specified period. In effect, L eq is the steady-state sound level containing the same acoustical energy as the time-varying sound that actually occurs during the same period. The 1-hour A-weighted equivalent sound level (L eq[h]) is the energy average of A-weighted sound levels occurring during a 1-hour period and is the basis for noise abatement criteria (NAC) used by Caltrans and FHWA. Percentile-Exceeded Sound Level (L xx ): L xx represents the sound level exceeded for a given percentage of a specified period (e.g., L 10 is the sound level exceeded 10 percent of the time, and L 90 is the sound level exceeded 90 percent of the time). Maximum Sound Level (L max ): L max is the highest instantaneous sound level measured during a specified period. Day-Night Level (L dn ): L dn is the energy average of A-weighted sound levels occurring over a 24-hour period, with a 10-dB penalty applied to A-weighted sound levels occurring during nighttime hours between 10 p.m. and 7 a.m. Community Noise Equivalent Level (CNEL) or Day-Evening-Night Level (L den ): Similar to L dn, CNEL or L den is the energy average of the A-weighted sound levels occurring over a 24-hour period, with a 10-dB penalty applied to A-weighted sound State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 28

48 Chapter 3 Fundamentals of Traffic Noise levels occurring during the nighttime hours between 10 p.m. and 7 a.m. and a 5-dB penalty applied to the A-weighted sound levels occurring during evening hours between 7 p.m. and 10 p.m Sound Propagation When sound propagates over a distance, it changes in level and frequency content. The manner in which noise reduces with distance depends on the following factors Geometric Spreading Sound from a localized source (i.e., a point source) propagates uniformly outward in a spherical pattern. The sound level attenuates (or decreases) at a rate of 6 db for each doubling of distance from a point source. Highways consist of several localized noise sources on a defined path and hence can be treated as a line source, which approximates the effect of several point sources. Noise from a line source propagates outward in a cylindrical pattern, often referred to as cylindrical spreading. Sound levels attenuate at a rate of 3 db for each doubling of distance from a line source Ground Absorption The propagation path of noise from a highway to a receiver is usually very close to the ground. Noise attenuation from ground absorption and reflective-wave canceling adds to the attenuation associated with geometric spreading. Traditionally, the excess attenuation has also been expressed in terms of attenuation per doubling of distance. This approximation is usually sufficiently accurate for distances of less than 200 feet. For acoustically hard sites (i.e., sites with a reflective surface between the source and the receiver, such as a parking lot or body of water), no excess ground attenuation is assumed. For acoustically absorptive or soft sites (i.e., those sites with an absorptive ground surface between the source and the receiver, such as soft dirt, grass, or scattered bushes and trees), an excess ground-attenuation value of 1.5 db per doubling of distance is normally assumed. When added to the cylindrical spreading, the excess ground attenuation results in an overall drop-off rate of 4.5 db per doubling of distance Atmospheric Effects Receivers located downwind from a source can be exposed to increased noise levels relative to calm conditions, whereas locations upwind can have lowered noise levels. Sound levels can be increased at large distances (e.g., more than 500 feet) from the highway because of atmospheric temperature inversion (i.e., increasing temperature with elevation). Other factors such as air temperature, humidity, and turbulence can also have significant effects. State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 29

49 Chapter 3 Fundamentals of Traffic Noise Shielding by Natural or Human-Made Features A large object or barrier in the path between a noise source and a receiver can substantially attenuate noise levels at the receiver. The amount of attenuation provided by shielding depends on the size of the object and the frequency content of the noise source. Natural terrain features (e.g., hills and dense woods) and human-made features (e.g., buildings and walls) can substantially reduce noise levels. Walls are often constructed between a source and a receiver specifically to reduce noise. A barrier that breaks the line of sight between a source and a receiver will typically result in at least 5 db of noise reduction. Taller barriers provide increased noise reduction. Vegetation between the highway and receiver is rarely effective in reducing noise because it does not create a solid barrier. State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 30

50 Chapter 4 Regulatory Setting Chapter 4. Regulatory Setting This report focuses on the requirements of 23 CFR 772, as described below Federal Regulations CFR 772 This regulation provides procedures for preparing operational and construction noise studies and evaluating noise abatement considered for federal and federal-aid highway projects. Under 23 CFR 772.7, projects are categorized as Type 1, Type 2, or Type 3 projects. FHWA defines a Type 1 project as a proposed federal or federal-aid highway project for the construction of a highway on a new location, or the physical alteration of an existing highway where there is either substantial horizontal or substantial vertical alteration, or increases the number of through-traffic lanes. A Type 2 project is a noise barrier retrofit project that involves no changes to highway capacity or alignment. A Type 3 project is a project that does not meet the classifications of a Type 1 or Type 2 project. Type 3 projects do not require a noise analysis. Type 1 projects include the addition of through traffic lanes that function as highoccupancy vehicle lanes, high-occupancy toll lanes, bus lanes, or truck climbing lanes. Type 1 projects include the addition of an auxiliary lane (except when an auxiliary lane is a turn lane); addition or relocation of interchange lanes or ramps; restriping existing pavement for the purpose of adding a through-traffic lane or auxiliary lane; and the addition of a new or substantial alteration of a weigh station, rest stop, ride-share lot, or toll plaza. Projects unrelated to increased noise levels, such as striping, lighting, signing, and landscaping projects, are not considered Type 1 projects. The proposed Project includes construction of highway in a new location, substantial horizontal alteration, and addition of traffic lanes as described under Alternatives 1 6A. Therefore, the proposed Project is categorized as a Type 1 Project according to 23 CFR 772. Under 23 CFR , noise abatement must be considered for Type 1 projects if the project is predicted to result in a traffic noise impact. In such cases, 23 CFR 772 requires that the project sponsor consider noise abatement before adoption of the final NEPA document. This process involves identification of noise abatement measures that are reasonable, feasible, and likely to be incorporated into the project, and of noise impacts for which no apparent solution is available. Traffic noise impacts, as defined in 23 CFR 772.5, occur when the predicted noise level in the design year approaches or exceeds the NAC specified in 23 CFR 772, or a State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 31

51 Chapter 4 Regulatory Setting predicted noise level substantially exceeds the existing noise level (i.e., a substantial noise increase). 23 CFR 772 does not specifically define the terms substantial increase or approach ; these criteria are defined in the Protocol (see Section below).. The NAC shown in Table 4-1correspond to various land use activity categories. Activity categories and related traffic noise impacts are determined based on the actual land use in a given area. Table 4-1: Activity Categories and Noise Abatement Criteria Activity Category Activity L eq[h], dba Evaluation Location Description of Activities A 57 Exterior Lands on which serenity and quiet are of extraordinary significance and serve an important public need and where the preservation of those qualities is essential if the area is to continue to serve its intended purpose. B 2 67 Exterior Residential. C 2 67 Exterior D 52 Interior E 72 Exterior F G Active sport areas, amphitheaters, auditoriums, campgrounds, cemeteries, day care centers, hospitals, libraries, medical facilities, parks, picnic areas, places of worship, playgrounds, public meeting rooms, public or nonprofit institutional structures, radio studios, recording studios, recreation areas, Section 4(f) sites, schools, television studios, trails, and trail crossings. Auditoriums, day care centers, hospitals, libraries, medical facilities, places of worship, public meeting rooms, public or nonprofit institutional structures, radio studios, recording studios, schools, and television studios. Hotels, motels, offices, restaurants/bars, and other developed lands, properties, or activities not included in A D or F. Agriculture, airports, bus Facilities, emergency services, industrial, logging, maintenance facilities, manufacturing, mining, rail facilities, retail facilities, ship facilities, utilities (water resources, water treatment, electrical), and warehousing. Undeveloped lands that are not permitted. Notes: L eq(h), dba = 1-hour equivalent continuous sound level, in A-weighted decibels 1 The L eq(h) activity criteria values are for impact determination only and are not design standards for noise abatement measures. 2 Includes undeveloped lands permitted for this activity category. Source: Federal Highway Administration 23 CFR 772. In identifying noise impacts, primary consideration is given to exterior areas of frequent human use. In situations where there are no exterior activities, or where the exterior activities are far from the roadway or physically shielded in a manner that prevents an impact on exterior activities, the interior criterion (Activity Category D) is used as the basis for determining a noise impact. State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 32

52 Chapter 4 Regulatory Setting 4.2. State Regulations and Policies Traffic Noise Analysis Protocol for New Highway Construction and Reconstruction Projects The Protocol specifies the policies, procedures, and practices to be used by agencies that sponsor new construction or reconstruction of federal or federal-aid highway projects. The NAC specified in the Protocol are the same as those specified in 23 CFR 772. The Protocol defines a noise increase as substantial when the predicted noise levels with project implementation exceed existing noise levels by 12 db. The Protocol also states that a sound level is considered to approach an NAC level when the sound level is within 1 db of the NAC identified in 23 CFR 772 (e.g., 66 dba is considered to approach the NAC of 67 dba, but 65 dba is not) (Caltrans 2011). The TeNS to the Protocol provides detailed technical guidance for the evaluation of highway traffic noise. This includes field measurement methods, noise modeling methods, and report preparation guidance (Caltrans 2009) Section 216 of the California Streets and Highways Code Section 216 of the California Streets and Highways Code relates to the noise effects of a proposed freeway project on public and private elementary and secondary schools. Under this code, a noise impact occurs if, as a result of a proposed freeway project, noise levels exceed 52 dba 1-hour A-weighted equivalent continuous sound level (L eq[h] ) in the interior of public or private elementary or secondary classrooms, libraries, multipurpose rooms, or spaces. This requirement does not replace the approach or exceed NAC criterion for FHWA Activity Category D for classroom interiors, but it is a requirement that must be addressed in addition to the requirements of 23 CFR 772. If implementing a project results in a noise impact under this code, noise abatement must be provided to reduce classroom noise to a level that is at or below 52 dba L eq(h). If the noise levels generated from freeway and nonfreeway sources exceed 52 dba L eq(h) prior to the construction of the proposed freeway project, then noise abatement must be provided to reduce the noise to the level that existed prior to construction of the project Local Regulations and Policies Placer County Noise Element The General Plan for Placer County (1994) contains policies governing noise related to development within Placer County, as identified below. The maximum allowable noise State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 33

53 Chapter 4 Regulatory Setting exposure limits for transportation noise sources in Placer County are summarized in Table 4-2. Table 4-2: Placer County Maximum Allowable Noise Exposure for Transportation Noise Sources Land Use Outdoor Activity Areas 1 Interior Spaces L dn/cnel L dn/cnel L eq, dba 2 Residential Transient Lodging Hospitals, Nursing Homes Theaters, Auditoriums, Music Halls 35 Churches, Meeting Halls Office Buildings 45 Schools, Libraries, Museums 45 Playgrounds, Neighborhood Parks 70 Notes: CNEL = community noise equivalent level 1 Where the location of outdoor activity areas is unknown, the exterior noise level standard shall be applied to the property line of the receiving land use. 2 As determined for a typical worst-case hour during periods of use. 3 Where it is not possible to reduce noise in outdoor activity areas to 60 Ldn/CNEL or less using a practical application of the best-available noise reduction measures, an exterior noise level of up to 65 dba Ldn/CNEL may be allowed provided that available exterior noise level reduction measures have been implemented and interior noise levels are in compliance with this table. Source: Placer County General Plan, Tahoe Regional Planning Agency CODE OF ORDINANCES Noise generated from construction activities is limited to between the hours of 8:00 a.m. and 6:30 p.m. on Monday through Saturday, based on Section 68.9 of the TRPA Code of Ordinances. Also, construction activities are prohibited on Sundays and federal holidays. TRPA has adopted standards for noise, including single-event standards for aircraft and other motorized vehicles and standards for cumulative noise events measured in terms of the 24-hour average noise metric CNEL for various land use categories and transportation corridors. CNEL is the time varying noise over a 24-hour period, with a 5-dB weighting factor applied to the hourly L eq for noises occurring from 7:00 p.m. to 10:00 p.m. (defined as relaxation hours) and a 10-dB weighting factor applied to noise occurring from 10:00 p.m. to 7:00 a.m. (defined as sleeping hours). The standards, established in the Goals and Policies, apply to the entire Lake Tahoe Region. Table 4-3 summarizes thresholds for single events (Lmax) and threshold for community noise events. State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 34

54 Chapter 4 Regulatory Setting Table 4-3: TRPA Regional Plan Cumulative Noise Levels Single Noise Events Boats (not to exceed any of 3 tests) Motor Vehicles (less than 6,000 pounds GVW) Motor Vehicles (greater than 6,000 pounds GVW) Motorcycles Off-road Vehicles Snowmobiles Noise Measurement 82 dba measured at 50 feet with engine at 3,000 rpm SAE test J1970 or SAEJ1970, Shoreline Test, 75 dba (standard adopted 7/03) SAE Test J2005, Stationary Test, 88 dba if watercraft manufactured on or after 1/1/93 and 90 dba if watercraft manufactured before 1/1/93 (standard adopted 7/03) 76 dba running at <35/mph (82 dba running at >35/mph) measured at 50 feet 82 dba running at <35/mph (86 dba running at >35/mph) measured at 50 feet 77 dba running at <35/mph (86 dba running at >35/mph) measured at 50 feet 72 dba running at <35/mph (86 dba running at >35/mph) measured at 50 feet 82 dba running at <35/mph measured at 50 feet Community Noise Equivalent Levels: Background levels shall not exceed the following: Land Use Category CNEL, dba High Density Residential 55 Low Density Residential 50 Hotel/motel facilities 55 Commercial area 65 Industrial 65 Urban Outdoor Recreation 55 Rural Outdoor Recreation 50 Wilderness and Roadless Areas 45 Critical Wildlife Areas 45 Policy Statement: It shall be a policy of the TRPA Governing Board in the development of the Regional Plan to define, locate, and establish CNEL levels for transportation corridors. Transportation 1 U.S (2) dba CNEL State Routes 89, 207, 28, 267 and 431 South Lake Tahoe Airport 55 (2) dba CNEL 60 (3) dba CNEL Notes: CNEL = community noise equivalent level measurements are weighted average of sound level gathered throughout a 24 hour period; db = decibels; dba = A-weighted decibels; mph = miles per hour; rpm = revolutions per minute 1 CNEL values for transportation corridor. 2 This transportation corridor threshold overrides the land use CNEL thresholds and is limited to an area within 300 feet from the edge of the road. 3 This threshold applies to those areas impacted by the approved flight paths. Source: Tahoe Regional Planning Agency Code of Ordinances 2012 State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 35

55 Chapter 4 Regulatory Setting CNEL levels are addressed in Appendix C. GOALS AND POLICIES The Goals and Policies document of the 1987 Regional Plan establishes an overall framework for development and environmental conservation in the Lake Tahoe region. Chapter II (Land Use Element) of the Goals and Policies document considers seven subelements, including the Noise subelement. The Goals and Policies document presents the overall approach to meeting TRPA s environmental carrying capacity thresholds (thresholds) (see Thresholds below). The following goals and policies in the Noise subelement of the Goals and Policies are relevant to the project: Goal 1. Single Event Noise Standards shall be attained and maintained. People can be annoyed by a specific noise source. Thresholds were adopted that apply to aircraft, boats, motor vehicles, off-road vehicles, and snowmobiles to reduce impacts associated with single noise events. Policy 3: Motor vehicles and motorcycles shall comply with the appropriate noise thresholds. Policy 6: The plan will permit uses only if they are consistent with the noise standards. Sound proofing practices may be required on all structures containing uses that would otherwise adversely impact the prescribed noise levels. Goal 2. Community noise equivalent levels shall be attained and maintained. CNEL thresholds were adopted to reduce the annoyance associated with cumulative noise events on people and wildlife. In the Lake Tahoe Basin, the main sources of noise are attributed to the major transportation corridors and the airport. Therefore, the policies are directed towards reducing the transmission of noise from those sources. The CNEL thresholds will be attained upon implementation of the following policies. Policy 1: Transmission of noise from transportation corridors shall be reduced. The noise associated with the transportation corridors can be decreased by reducing the number of trips and by installing mitigation measures. Trip reduction will be accomplished by the transit improvements identified in the Transportation Element. Ordinances will establish specific site design criteria for projects to help reduce the transmission of noise from the transportation State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 36

56 Chapter 4 Regulatory Setting corridors. The design criteria will also be incorporated into the water quality and transportation improvement programs. The mitigation measures may include setbacks, earth berms, and barriers. As a form of zoning, TRPA has divided the Lake Tahoe Region into more than 175 separate Plan Areas. For each Plan Area, a Statement is made as to how that particular area should be regulated to achieve regional environmental and land uses objectives. As part of each Statement, an outdoor CNEL standard is established based on the Thresholds. TRPA has established noise standards in community noise equivalent levels (CNEL) measured in dba over a 24 hour period. TRPA thresholds establish different limits for different uses. The noise limitations of Chapter 23 of the TRPA Code apply; however, the Community Plan Area Statement establishes equal or superior standards pursuant to the noise thresholds. Placer County will use the TRPA and CP rules for noise. TRPA Thresholds are 65 CNEL for commercial areas, 55 CNEL for residential and urban recreation, and 55 CNEL for highway corridors. Based on CNEL values for transportation corridors, 55 dba CNEL would be applied for SR 28 and SR 89, as also shown in Table 4-3. TRPA thresholds establish different limits for different uses. The noise limitations of Chapter 23 of the TRPA Code apply; however, the Community Plan Area Statement establishes equal or superior standards pursuant to the noise thresholds. Placer County will use the TRPA and CP rules for noise. The maximum cumulative noise equivalent levels for Tahoe City Community Plan area are as follows: Where applicable, a maximum 55 CNEL override for the Highway 28 and Highway 89 corridors is permissible. The maximum CNEL for Special Areas #3 and #4 and #5 is 55 CNEL. The maximum CNEL for all areas of the Community Plan except as noted in 1 and 2 above is 65 CNEL. The maximum CNEL for Shorezone Tolerance Districts 4, 6 and 7 is 55 CNEL and the maximum for the lakezone is 50 CNEL. Figure 3 of the Tahoe City Community Plan (attached in Appendix C of this report) shows Specials areas within the Community Plan Area Boundary. All the receivers studied under this project are located within Special areas 1 through 5. Therefore, based State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 37

57 Chapter 4 Regulatory Setting on the CNEL standards of the Tahoe City Community Plan area, the threshold for all receivers would be considered as 55 db CNEL. State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 38

58 Chapter 5 Study Methods and Procedures Chapter 5. Study Methods and Procedures 5.1. Selection of Receivers and Measurement Sites Preliminary selection of receivers for modeling and measurement was made based on the distance from roadway rights of way within the project area, aerial photographs of the project area, and an initial field visit. As stated in the Protocol, noise abatement is only considered for areas of frequent human use that would benefit from a lowered noise level. Although all developed land uses are evaluated in this analysis, the focus is on locations of frequent human use that would benefit from a lowered noise level. Accordingly, this impact analysis focuses on locations with defined outdoor activity areas, such as residential backyards and common use areas at hotels/motels in the project vicinity. The geographical features of the project area relative to nearby existing land uses also were identified. Five short-term (ST) noise measurement locations were selected to represent the major developed area within the project area along the existing portion of the project roadway segments. Two long-term (LT) measurement sites were selected to capture the diurnal traffic noise level pattern in the project area. The short-term measurement locations were selected to serve as representative modeling locations at noise sensitive areas. An additional 61 non-measurement locations were selected as modeling locations. In total, 67 receiver locations were modeled to represent the noise sensitive land uses in the project vicinity. The monitoring and modeled receiver locations are shown in Figure 5-1. Receiver locations were then refined, based on the results of a field visit, maps, and photographic data. Modeled receiver placement focused on areas of frequent human use associated with residential units or recreational areas. Measurement points are identified as ST-01 through ST-05. ST-01 and ST-03 were used to calibrate the FHWA Traffic Noise Model, version 2.5 (TNM 2.5) relative to the distribution of traffic noise. The traffic counts were expanded to hourly volumes (multiplied by 4 to normalize the results to hourly values) and entered into TNM 2.5 for the monitoring site. All measurement points represented areas of frequent human use. State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 39

59 Chapter 5 Study Methods and Procedures 5.2. Field Measurement Procedures A field noise study was conducted in accordance with recommended procedures in the Caltrans TeNS document (Caltrans 2009). The following is a summary of the procedures used to collect short-term and long-term sound level data Long-Term (LT) Measurement Long-term (24-hour) noise measurements were taken to determine the loudest hour or period within the Project area. Two long term noise measurements were conducted; during the summer time and winter time, from Thursday July 5 through Friday July 6, 2012, and from Friday January 10 to Saturday January 11, 2014, respectively. The LT noise measurements were captured in 1-hour intervals to determine the loudest hour or hours. During the LT measurements, the sound level meter was unattended, and no traffic data were collected. The LT measurement was taken near the intersection of SR 89 and SR 28 at Tahoe Marina Lodge at 270 North Lake Boulevard (SR 28), 85 feet from the SR 28 centerline and at 55 West Lake Boulevard (South SR 89), 90 feet from the South SR 89 centerline. The locations of the long term noise measurements are shown in Figure Short-Term (ST) Measurements Five short term (15-minute) noise measurements were conducted at representative receiver sites, classified as Activity Categories B, C, and E within the project area, on Thursday and Friday, July 5 and July 6, 2012, between 7:00 a.m. and 6:30 p.m. when traffic was free-flowing. The ST measurement locations are shown in Figure 5-1. The following measurement procedures were utilized: calibrating the sound level meter; setting up the sound level meter at a height of 5 feet; commencing the noise monitoring; collecting site-specific data, such as date, time, direction of traffic, and distance from the sound level meter to the right-of-way; counting passing vehicles for a period of 15 minutes (vehicles were split into three categories: heavy trucks, medium trucks, and automobiles); stopping measurement after 15 minutes; and State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 40

60 Chapter 5 Study Methods and Procedures Source: AECOM 2014 Figure 5-1: Noise Measurement and Receiver Locations State Route 89/Fanny Bridge Community Revitalization Project Noise Study Report 41